Abstract: A tubular grid exhaust fume conducting heat exchanger is mounted on a horizontal top face of the fuel mixture manifold of an internal combustion motor, said grid supporting vertically centrally thereon a cylindrical tubular fuel and air mixing housing the upper end of which supports and receives air from an air filter, the lower portion of which housing has a butterfly valve mounted therein and connects downwardly, directly through said heat exchanger with said fuel mixture manifold.A jacketed and exhaust fume warmed fuel reserve canister provides a screen bottomed chamber which encloses a spherical plastic float and admits fuel axially downwardly into said chamber through a flow governing needle valve closed by said float when said float is lifted in said chamber by the fuel rising to its normal operating level.